The invention relates to a means or device for fighting fire in at least one cable or line run containing a cable and/or a line, at least one pipe, which contains a fire-extinguishing agent under positive pressure and is laid continuously in the cable or line run, and the wall of this pipe is produced from a material whose melting point is chosen to be equal to or lower than the ignition point of the cable sheath or the line.
A means of this type is disclosed by DE-A1-27 45 370.
The brochure from Walther & Cie. AG on "Spruhflutanlagen fur Transformatoren und Kabelkanale" [Spray flooding systems for transformers and cable ducts] 3/72 discloses an extinguishing device in which a pipe which has a large number of extinguishing nozzles is laid in a cable duct. In the event of fire, a liquid extinguishing agent is forced into the pipe from a central control point and is thus sprayed out by the spray nozzles. Since the entire system, or at least in each case a relatively large part thereof, is placed under pressure, the extinguishing agent emerges within the entire system, or within a relatively large part thereof, and the cable duct is flooded.
EP-A2 0 077 679 discloses a fire-protection system in which a cable duct has a large number of small flexible containers having coverings made from a crosslinked polymer material. These small containers contain a nonflammable liquid, in particular water. The coverings are constructed somewhat like a cushion and are arranged one behind the other. If a fire breaks out, then the heat produced is to a certain extent absorbed by the evaporation of the liquid in the interior of the small containers, without the latter bursting. In this way, since heat is drawn off, the action of the heat may last longer. If the heat rises further, then the covering of some of the small containers tears apart, and the evaporated liquid flows out. The small containers are expediently only partly filled with the liquid, so that they can expand to a greater extent. However, the production of such small containers that are filled with a liquid and lined up in a row is extremely complicated.
DE-A1 33 37 532 discloses an extinguishing device having a container which is intended to accommodate an extinguishing agent that is under pressure, and to which there is connected a piece of pipe which, in the region of its end, is closed by a wall. This wall consists of a material which dissolves or liquefies when a predetermined temperature is exceeded.
U.S. Pat. No. 5,276,433 discloses a temperature sensor which is incorporated, for example, in the outlet of a ventilation system. It contains a pipe which consists of plastic and is filled with a liquid under pressure. When this pipe is subjected to a high temperature, the liquid in the interior of the pipe begins to boil and the pipe bursts, the pressure drop which is produced, is used to close the ventilator flaps.
GB-A 1 357 010 discloses a fire-extinguishing device which is intended to be incorporated in a housing that is exposed to the risk of fire. It is possible for the housing to contain, for example, a television receiver, a computer, a photocopier, an office machine or a motor. Laid in the housing is a pipe which contains a liquid fire-extinguishing agent under pressure. In the event of fire, the pipe becomes soft, bursts and the liquid flows out.
In the case of a means for fighting fires, which means has at least one pipe which contains a fire-extinguishing agent under pressure and the wall is of a material with a melting point that is equal to or less than the ignition point of the cable sheath or line. The extinguishing agent must be kept in the pipes for a long period of time. During these long standing times, the extinguishing agent may undergo changes.